醛酮还原酶1B10基因沉默对MHCC97H细胞生长和基因表达的影响

目的 探讨醛酮还原酶1B10(AKR1B10)基因在肝癌发生和发展过程中的作用及其机制.方法 化学合成AKR1B10序列特异性小干扰RNA,用脂质体LipofectaminrTM2000介导转染人肝癌细胞系MHCC97H,设实验组转染AKR1B10-小干扰RNA,设阴性对照组转染非编码序列双链小RNA,设空白对照组不作转染.用实时定量PCR、Western blot和酶活性检测法检测AKR1B10 mRNA和蛋白的表达情况,用细胞计数试剂盒CCK-8检测转染细胞的生长增殖变化,用流式细胞仪检测膜联蛋白V/碘化丙啶双标记的凋亡细胞变化,并用实时定量PCR检测c myc、c-fos、N-ras、ki-67、caspas 3、bax肿瘤相关基因的表达变化.用析因设计的方差分析和完全随机方差分析进行组间比较,LSD法进行多重比较.结果 转染24、48 h和72 h后,AKR1B10 mRNA的相对表达量在实验组分别为0.382±0.048、0.098±0.008和0.257±0.032;阴性对照组分别为0.797±0.092、0.742±0.086和0.794+0.105;空白对照组分别为0.808±0.118、0.716±0.083和0.706±0.067.不同转染时间和不同实验组中AKR1B10 mRNA的表达比较,F值分别为11.650和566.971,P值均＜0.01,差异均有统计学意义.转染24、48 h和72 h后,实验组的AKR1B10mRNA表达较空白对照组被明显抑制,抑制率分别为52.7%±5.6%、86.3%±4.4%和63.7%±6.1%,以转染48 h的抑制率最高(t=80.68,P＜0.01);阴性对照组的表达水平接近空白对照组(P＞0.05).Western blot结果显示,转染24、48 h和72 h后,实验组的AKR1B10蛋白表达水平均有下降,其中以转染72 h的降低幅度最大;阴性对照组的表达水平接近空白对照组.转染24、48、72h和96h后,实验组450nm处吸光度值分别为1.465±0.040、1.724±0.106、1.934±0.069和2.377±0.163;阴性对照组分别为1.528±0.044、2.019±0.091、2.711±0.204、3.151±0.159;空白对照组分别为1.567+0.057、2.102±0.099、2.642±0.198、3.069±0.180;不同转染时间和不同实验组间比较,F值分别为128.092、36.535,P值均＜0.01,差异均有统计学意义.转染了AKR1B10-siRNA的MHCC97H细胞生长受到抑制.与空白对照组相比,实验组的细胞生长抑制率在转染48、72 h和96 h分别为18.0%±1.6%、26.1%±3.2%和22.5%±1.1%,t值分别为19.197、13.093和23.553,P值均＜0.01,差异均有统计学意义;阴性对照组的细胞生长未受到明显抑制(P＞0.05).实验组、阴性对照组和空白对照组各基因mRNA的相对表达量:c-myc基因分别为1.047±0.156、1.737±0.193和1.631±0.128;c-fos基因分别为0.041+0.003、0.082±0.006和0.081±0.004; N-ras基因分别为0.082±0.009、0.156±0.013和0.133±0.015;ki-67基因分别为0.032±0.002、0.070±0.008和0.069±0.005; caspasc-3基因分别为0.148±0.018、0.110±0.009和0.108+0.012;bax基因分别为0.780±0.092、0.629±0.058和0.617±0.073,各基因的mRNA在不同组别表达差异均有统计学意义(F值分别为104.384、400.915、211.903、427.041、67.750和37.272,P值均＜0.01).结论 AKR1B10可能通过调节肿瘤相关基因的表达水平来促进细胞增殖、抑制细胞凋亡.

Effects of AKR1B10 gene silence on the growth and gene expression of HCC cell line MHCC97H

Objective To explore the biological function and possible underlying mechanism of aldo-keto reductase family 1 member B10 (AKR 1B 10) gene during hepatocarcinogenesis. Methods A pair of chemically synthesized small interfering RNA (siRNA) targeting on AKR1B10 was transfected into liver cancer cell line MHCC97H by LipofectamineTM 2000. After confirming the interfering effects ofAKR1B10-siRNAs through Quant SYBR Green polymerase chain reaction (Real-time PCR), Western blot and enzymatic activity assay, the capabilities of proliferation and apoptosis of the transfected cells were observed by CCK-8 assay and flow cytometry analysis, and the expressions of a group of tumor-related gene such as cmyc, c-fos, N-ras were observed through Real-time PCR. Results The expressions of AKR1B10 and the enzymatic activity were down-regulated significantly in AKR1B10-siRNA-transfected cells. Compared with mock and blank control groups, cell growth in AKR1B10-siRNA-transfected group was inhibited by 26.6% ± 3.1% at 72 h after transfection. The ratio of apoptotic cells was 37.3% ± 1.0% in AKR 1B 10-siRNA-transfected group,which was significantly higher than that in mock and blank control groups (P ＜ 0.01). Real-time PCR showed that the expressions of oncogene c-myc, c-fos and N-ras, and the proliferation-associated gene ki-67 were down-regulated in AKR1B10-siRNA-transfected cells, while the expressions of apoptosis-promoting gene caspas-3 and bax were up-regulated. Conclusions AKR1B10 might promote proliferation, inhibit apoptosis and then induce malignant transformation of hepatocytes by regulating the expression level of some tumorrelated genes.